Well, I am not certain but it probably goes something like this...
You start off with a strong amp like a Line 6 Vetta II.
Have some electronics whiz hot rod it for you.
Spend a year dialing in the coolest sound you can possibly get out of it.
Put it in a well tuned tracking room with just the right amount of audio treatment.
Crank up the volume to 11.
Put a high-end dual ribbon mike in front of it with a $3000 preamp dialed to the perfect impedance.
Spend about 6 days finding the sweetest spot in the room.
Record duplicate tracks to layer over top of each other.
Have three high paid engineers clean and tweak all those tracks.
Have them mixed down on a $450,000 Sony Oxford console.
Hand it over to the best Mastering Engineer on the planet.
Stir vigorously, bake 4 months, and enjoy.
